Opal had 1660 mℓ more soy milk than Nora. After Opal gave Nora 550 mℓ of soy milk, the ratio of Opal's soy milk to Nora's soy milk became 5 : 3. How much soy milk did Opal have at first? Give your answer in millilitres.
| |
Opal |
Nora |
Difference |
| Before |
1 u + 1660 |
1 u |
1660 |
| Change |
- 550 |
+ 550 |
|
| After |
1 u + 1110 |
1 u + 550 |
560 |
Comparing Opal and
Nora in the end |
5 p |
3 p |
2 p |
Volume of soy milk that Opal had in the end
= 1 u + 1660 - 550
= 1 u + 1110
Difference in the volume of soy milk between Opal and Nora in the end
= 5 p - 3 p
= 2 p
2 p = 1110 - 550
2 p = 560
1 p = 560 ÷ 2 = 280
Volume of soy milk that Opal had at first
= 5 p + 550
= 5 x 280 + 550
= 1400 + 550
= 1950 mℓ
Answer(s): 1950 mℓ
